Ictiofauna da Estação Experimental Agronômica da Universidade Federal do Rio Grande do Sul, sul do Brasil: composição e diversidade

The ichthyofauna of the Estacao Experimental Agronomica of the Universidade Federal do Rio Grande do Sul was inventoried. We sampled three localities in the arroio Calombos and nine small dams. Overall 10,786 specimens were collected, belonging to seven orders, 18 families, 34 genera, and 51 species. Additional samples were taken in swampy and temporary areas, besides the analysis of fish collection records, resulting in a total of 61 species in 42 genera of fishes in the EEA/UFRGS. Orders Characiformes and Siluriformes predominated in richness and abundance. Most abundant species were Hyphessobrycon igneus, H. meridionalis, H. luetkenii, Cheirodon interruptus, Geophagus brasiliensis, and Crenicichla lepidota, respectively. The sites of the stream presented higher species richness (39 spp.) than small dams (25 spp.), being 13 species common to both environments. The record of Micropterus salmoides (black bass) in three of the small dams is associated with the lowest richness, demonstrating the impact of the presence of a predatory exotic species over native species. The seine net presented the best results to capture a larger number of species and a wider range of size of specimens. As an area of university education, the EEA/UFRGS serves as an important source for fish diversity studies. The conservation of the physical-chemical and biological integrity of the water environments is recommended to conserve this biodiversity. A key to identification of fish species is presented here.